IRR - I 90 over Int Dunmore
FairBig Horn County, Montana · 5.6M N Crow Agency · Structure no. I00090503+02872
- Built
- 1959
- 66 years old
- Condition
- Fair
- inspected October 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 119 ft
- 3 main spans
- Daily traffic
- 4,473
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
IRR - I 90 over Int Dunmore is a prestressed concrete stringer/multi-beam or girder carrying IRR - I 90 over Int Dunmore in Big Horn County, Montana. It was built in 1959, so it is 66 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 4,473 vehicles a day, roughly 18% of them trucks, projected to reach 4,696 by 2043. The structure is 119 ft (36.3 m) long and 42 ft wide.
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was IRR - I 90 over Int Dunmore built?
It was built in 1959, making it 66 years old in 2025.
What condition is IRR - I 90 over Int Dunmore in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2023.
How much traffic does IRR - I 90 over Int Dunmore carry?
About 4,473 vehicles per day (2023 count), of which roughly 18% are trucks.
How long is IRR - I 90 over Int Dunmore?
The structure is 119 ft (36.3 m) long with a longest span of 47 ft (14.3 m) and a deck 42 ft wide.
Who owns IRR - I 90 over Int Dunmore?
It is owned by the State Highway Agency.